Development of Inference Models for Estimating Seismic Site Conditions in Taiwan

From observation of previous earthquakes, site effect has a great influence on ground motions. In many earthquake-resistant design codes for buildings, the design ground motion would be specified according to the local site condition. To characterize the site condition, the average shear wave velocity of the upper 30 meter of the ground (Vs30) is often used. The stiff the site (e.g. rock) is, the higher the Vs30. To obtain the shear wave velocity, geophysical measurement (e.g suspension logging) can be performed. Although direct measurement of shear wave velocity is much more accurate, it may be costly and may not be possible for area with difficult access, proxies to estimate shear wave velocity can be used instead. In this research, different proxies (e.g. geology, slope, geomorphic features) are considered to develop inference models for estimation of Vs30 in Taiwan.